I recommend you will almost always need a new liner. The only chance you will not need one is if you have an older natural venting appliance and the flue tiles are in good shape. The reason for this is because the older appliances send a good amount of heat up the chimney. The gases then have limited condensation time. All newer appliances are going to need a new liner. They are just too efficient.
For years, people throughout the greater Milwaukee and Waukesha areas have been turning to Smoke Stacks, Inc. for their chimney repair and relining needs. At Smoke Stacks, Inc. we believe that attention to detail, professional work, courteous service and honest prices are the qualities that make the difference.